Data and information exchange are crucial for any kind of scientific research activities and are becoming more and more important. The comparison between different data sets and different disciplines creates new data, adds value, and finally accumulates knowledge. Also the distribution and accessibility of research results is an important factor for international work. The gas hydrate research community is dispersed across the globe and therefore, a common technical communication language or format is strongly demanded. The CODATA Gas Hydrate Data Task Group is creating the Gas Hydrate Markup Language (GHML), a standard based on the Extensible Markup Language (XML) to enable the transport, modeling, and storage of all manner of objects related to gas hydrate research. GHML initially offers an easily deducible content because of the text-based encoding of information, which does not use binary data. The result of these investigations is a custom-designed application schema, which describes the features, elements, and their properties, defining all aspects of Gas Hydrates. One of the components of GHML is the "Field Data" module, which is used for all data and information coming from the field. It considers international standards, particularly the standards defined by the W3C (World Wide Web Consortium) and the OGC (Open Geospatial Consortium). Various related standards were analyzed and compared with our requirements (in particular the Geographic Markup Language (ISO19136, GML) and the whole ISO19000 series). However, the requirements demanded a quick solution and an XML application schema readable for any scientist without a background in information technology. Therefore, ideas, concepts and definitions have been used to build up the modules of GHML without importing any of these Markup languages. This enables a comprehensive schema and simple use. An extensive documentation ensures the usability of the "Field Data" module consisting of a detailed explanation integrated in the application schema, an HTML-based document, and a detailed documentation. Because of the close collaboration of gas hydrate experts and specialists in Geoinformatics, the application schema of GHML is user-oriented and contains all possible aspects of this research field. The usability is the assessment factor for GHML.